1. Field
Embodiments of the present invention relate to an energy storage device and a method for decreasing a rush current.
2. Description of the Related Art
In a high-capacity energy storage device, such as an energy storage system (ESS), a plurality of battery packs may be configured by coupling battery cells (e.g., scores or several hundreds of battery cells) to each other in series and/or in parallel, and the battery packs may be coupled to each other in parallel to thereby maintain driving voltage and efficiently output energy.
Herein, when one battery pack is removed from the energy storage system and is then reconnected thereto, if there is a potential difference between an already coupled battery pack and the battery pack to be reconnected, a rush current is generated, which reduces the potential difference.
Battery management systems (BMSs) or battery cells may be damaged by the rush current. Therefore, reducing or minimizing the rush current is a way to improve stability of battery packs and to increase lifetimes thereof.